SB 6.11.21

The words aham samadhaya manah indicate that the most important duty at the time of death is to concentrate one's mind. If one can fix his mind on the lotus feet of Krsna, Visnu, Saṅkarsana or any Visnu murti, his life will be successful. To be killed while fixing his mind at the lotus feet of Saṅkarsana, Vrtrasura asked Indra to release his vajra, or thunderbolt. He was destined to be killed by the thunderbolt given by Lord Visnu; there was no question of its being baffled. Therefore Vrtrasura requested Indra to release the thunderbolt immediately, and he prepared himself by fixing his mind at the lotus feet of Krsna. A devotee is always ready to give up his material body, which is described herein as gramya-pasa, the rope of material attachment. The body is not at all good; it is simply a cause of bondage to the material world. Unfortunately, even though the body is destined for destruction, fools and rascals invest all their faith in the body and are never eager to return home, back to Godhead.